Thickness evolution of the Scandinavian Ice Sheet during the Late Weichselian in Nordfjord, western Norway: evidence from ice-flow modeling

Abstract

Results from experiments with a two-dimensional ice-flow model, applied along a west-east transect in western Norway, provide new constraints on the thickness evolution of the Scandinavian Ice Sheet throughout the Late Weichselian glaciation and deglaciation. Investigations took place along an E-W flowline of the former ice sheet at c. 62 N, from the modern glacier Jostedalsbreen, through the Nordfjord, and across the continental shelf. A paleoclimate record from Kråkenes, which is located directly at the flowline, provides temperature and precipitation information for the time between 13 800 and 9200 cal. yr BP.LGM climate conditions for the study area are estimated from various GCM studies. The GISP2 d 18O record has been tuned to the local data in order to provide a continuous temperature record as input for time-transgressive model runs. The results of all experiments suggest that the ice did not cover the highest mountain peaks in this area, and that nunataks persisted throughout the Late Weichselian glaciation. These findings are in contrast to results from many previous model studies and other ice-sheet reconstructions, but agree well with minimum thickness estimates from cosmogenic dating and with vertical ice limits inferred from lower block field boundaries and trimlines.

Younger Dryas sea level and meltwater pulse 1B recorded in Barbados reef crest coral Acropora palmata

“…We suggest focused moisture delivery by the North American Jet Stream promoted ice sheet resurgence in the Fennoscandian region during the Younger Dryas [ Winguth et al , ; Cuffey and Paterson , ] as recorded in lower equilibrium line altitudes in Norway [ Larsen and Stalsberg , ] and early cessation of retreat and ice sheet readvances in some areas of Fennoscandinavia [ Andersen et al , ]. The Younger Dryas sea level response, observed as a slowdown, matches the expected global ice volume response to an advancement of the Fennoscandian ice sheet in combination with reduced melting of the Laurentide and Greenland ice sheets.…”

“…Had the rate of sea level rise at Barbados increased uniformly at the rates observed from 13.9 to 13 kyr B.P., sea level would be predicted to have been higher by about 8 m by the end of the Younger Dryas (i.e., 50 rather than 58 mbsl). Therefore, reconciliation of an ~ 8 m “sea level deficit” (2.9 million km 3 ice volume equivalent) can be achieved by the focused regeneration of the Fennoscandian ice sheet [e.g., Winguth et al , ] in conjunction with reduced Laurentide and Greenland melting.…”

Low genetic and morphological differentiation in the European species complex ofRosa sherardii,R. mollisandR. villosa(RosasectionCaninaesubsectionVestitae)

“…ex Gaudin (Stehlik, ). The northern populations ( R. mollis ) probably grew in non‐glaciated regions that existed in, for example, southern Norway (Nesje & Dahl, ; Arnold et al ., ) or on nunataks (Winguth et al ., ; Linge et al ., ; Paus et al ., 2006), as could be shown for Arenaria humifusa Wahlenb. and Sagina caespitosa (J.Vahl) Lange (Westergaard et al ., ).…”

Relict Blockstreams at Insteheia, Valldalen-Tafjorden, Southern Norway: Their Nature and Schmidt Hammer Exposure Age

“…Although there has been considerable debate about ice thicknesses and the extent of ice‐free terrain in this northwestern part of southern Norway at the LGM (e.g. Nesje et al ., ; Follestad, ; Brook et al ., ; Winguth et al ., ), the upper altitudinal limit of the ice sheet appears to have lain at 1400–1800 m asl with a steep gradient towards the North Atlantic, which leads to uncertain estimates of the deglaciation date at Insteheia. Ground over 900–1000 m asl may have been ice‐free by 16–15 ka as a consequence of rapid down wastage (Goehring et al ., ).…”